Planning a lateral before even starting FT?

Is this person genderfluid? Because you switched between male and female pronouns. Or is younger cousin just a euphemism for yourself?

In all seriousness, "your cousin" should probably start networking now. Assuming s/he/they/xir/whatever gained a few contacts during the original FT recruiting process, now would be a good time to reach back out to those people and let them know of your/her/his/their/xir's new gig and that you'd like to meet for coffee (assuming you're in the same location). Keep in contact with these people while working. Then about 6 or so months in, you/s/he/they/xir can be more "aggressive" in letting these people know your intentions and desire to lateral.

I haven't done this nor do I know anyone who has, but if I were to try to lateral this is essentially what I'd do. Hopefully someone who has done something similar can chime in.